BUTTER-C
Signature ingredients
Zinc gluconate gel OEM/ODM manufacturing
Zinc Gluconate Gel · Signature Ingredients · OEM/ODM
Zinc gluconate (INCI: Zinc Gluconate) is the zinc salt of gluconic acid, a white powder that dissolves readily in water and is a familiar ingredient in toners, gels and products for oily skin. What is rarely spelled out is that most of the clinical data on it come from oral tablets in a drug setting: a randomized, double-blind trial in 332 people with inflammatory acne compared zinc gluconate tablets with an oral antibiotic. Topical data are far thinner — the two studies we found both used multi-ingredient formulas (with salicylic acid, niacinamide), both in people with acne, most authors being company employees, and there is no trial comparing topical zinc gluconate alone with a vehicle. That is limited evidence, not enough for this gel to promise anything about acne or sebum. What is firm is the regulation: zinc gluconate is named directly in ASEAN Annex III (Ref 24), and total zinc from all water-soluble zinc salts must not exceed 1% calculated as zinc — about 6.96% of the anhydrous salt. Butter-C’s zinc gluconate gel is therefore an oil-free gel for oily and combination skin: zinc calculated from the COA, a gel base chosen to tolerate zinc ions, and claims that stop at “helps skin feel less oily, reduces shine” once measured on the finished product itself. Butter-C offers full-service OEM/ODM manufacturing, from formula development and testing to labeled finished product with its notification dossier.
Formula base
Zinc gluconate in an oil-free gel base that tolerates zinc ions
The general moisturizing gel page covers gel frameworks and humectants; this page makes zinc gluconate the signature ingredient. A zinc salt is an electrolyte, so the gel base has to be chosen around it rather than adding zinc to an existing base.
Zinc Gluconate — the signature ingredient
According to PubChem (CID 443445), the anhydrous form is C12H22O14Zn, 455.7 g/mol; the trihydrate is 509.7 g/mol (CID 71586951). The CIR report describes a white powder, freely soluble in water and very slightly soluble in alcohol; its declared function is skin conditioning — a technical function, not a claim. The 2016 industry survey compiled by CIR lists a maximum of 3% in leave-on products — a level seen on the US market, not a recommendation; the actual level is set by stability and tolerance testing (formulation experience).
An electrolyte-tolerant gel framework
Zinc salts can thin anionic polymer gels such as Carbomer (internal practice, to be tested on samples). The zinc gluconate gel uses Hydroxyethylcellulose, Xanthan Gum or Sclerotium Gum — non-ionic or less electrolyte-sensitive polymers — and viscosity is measured after the zinc salt is added, at the highest intended level.
Hydration for oily skin
Glycerin, Propanediol, Betaine, Panthenol and Sodium Hyaluronate hold water in the stratum corneum; oily skin still needs water. This group is the basis for a moisturizing claim. Sodium Hyaluronate is an anionic polymer, so viscosity is fixed on the complete formula with zinc.
Preservation and pH
Phenoxyethanol (maximum 1% — Annex VI) with Ethylhexylglycerin; the zinc salt does not replace the preservative, and a challenge test is still required. At alkaline pH zinc may cause haze or sediment; the internal monograph sets pH 4–6.5 (internal practice, confirmed by stability testing). EDTA is not added by habit, since strong chelating agents can bind zinc ions.
Key technical points
Four points specific to putting zinc gluconate into a gel
The issues below come from the zinc salt itself: zinc calculation under Annex III, anhydrous versus hydrated forms, incompatibilities in a water system and the limits of the safety data.
Calculating zinc under Annex III Ref 24
Ref 24 (release 2026-1, 22 June 2026) reads “Water-soluble zinc salts with the exception of zinc 4-hydroxy benzene sulphonate (entry 25) and zinc pyrithione (entry 101 and Annex VI, entry 8)”, with listed names “Zinc acetate, zinc chloride, zinc gluconate, zinc glutamate” and footnote (20) “The types of salts is not be limited to those listed in this reference.”, maximum concentration in the ready-for-use preparation “1% calculated as zinc”; the field-of-application and label-warning columns are blank. Unlike zinc PCA, zinc gluconate is named directly, so the entry applies as written. Zinc content: about 14.4% for the anhydrous form and 12.9% for the trihydrate → 1% zinc corresponds to about 6.96% anhydrous salt or 7.79% trihydrate (calculated from PubChem molecular weights, Zn 65.4 g/mol; zinc fraction rounded up, salt amount rounded down — the cautious direction).
Adding up all water-soluble zinc salts
When the formula also contains zinc PCA (about 20% zinc) or another soluble zinc salt, total zinc is the figure checked against 1%. Example from Butter-C’s ingredient article: 2% anhydrous zinc gluconate (about 0.29% zinc) plus 1% zinc PCA (about 0.21% zinc) gives about 0.5% zinc. Zinc pyrithione and zinc phenolsulfonate have their own entries and are excluded from Ref 24. The exact figure is calculated from the % zinc and salt form on each batch COA.
Incompatibilities in a water system
Zinc salts are electrolytes (they thin anionic polymer gels); strong chelators such as EDTA can bind zinc ions; alkaline pH risks haze or sediment — these points are internal practice and chemical inference, to be tested on samples. Method: dissolve the zinc salt in the water phase, add it after the gel has formed or test the order of addition, and check clarity at 4 °C.
Safety data: enough for a conclusion, thin on detail
The CIR Expert Panel (Scott et al., 2024) concluded that 27 zinc salts, including zinc gluconate, are safe in cosmetics in the present practices of use and concentration described, when formulated to be non-irritating. Specific human skin data amount to one 48-hour occlusive patch test on 11 people with a face and neck cream containing 0.05% zinc gluconate (no irritation) — so the finished product is tolerance-tested before sign-off. CIR also notes that heavy-metal impurities in zinc salts must be controlled. Butter-C does not use zinc gluconate in intranasal products (CIR records damage to nasal tissue, and a case series of 17 people reported reduced or lost sense of smell after intranasal zinc gluconate gel).
Three formulation directions
Three zinc gluconate gels for three customer groups
Clear zinc gluconate – panthenol gel
Oil-free, fragrance-free; zinc gluconate, glycerin, betaine and panthenol in a Hydroxyethylcellulose framework. Absorbs quickly and breaks into water when spread — for oily skin in hot, humid climates, morning and evening.
Zinc gluconate – niacinamide gel for oily skin
Adds 2% niacinamide — the level of the human sebum trial cited on the niacinamide & zinc serum page. The cream in a split-face study containing zinc gluconate also included niacinamide, but it is a different formula and its results are not borrowed. The phrase “helps reduce the look of shine” is used only after measurement on the finished product itself, as a claim of the whole formula.
Light zinc gluconate gel-cream for combination skin
A small amount of Squalane and Caprylic/Capric Triglyceride emulsified with a non-ionic emulsifier turns the gel milky and softer than the clear version — for dehydrated combination skin in air-conditioned rooms. Electrolytes can weaken an emulsion: centrifugation and freeze–thaw cycling are run on the complete formula with zinc. This version is not labeled “oil-free”.
Packaging is part of the formula
Flip-top tubes or pump bottles are more hygienic than open jars; gaskets and pumps are soak-tested with the sample because metal ions can interact with materials. Checked sources give no data on the light sensitivity of zinc gluconate — packaging is chosen for the other ingredients and on stability results.
Parameters we monitor
What our R&D lab measures on each sample
These are the parameters Butter-C monitors during formula development and scale-up. Specific limits are agreed with you on the approved sample and then written into the product’s in-house specification.
- Raw material COA
- Zinc gluconate per batch: anhydrous or trihydrate, % zinc, heavy metals (CIR cites the FCC food standard: cadmium and lead no more than 2 mg/kg each); identity against the retained sample.
- Appearance & clarity
- Color, odor and clarity against the reference sample; watch for haze or white precipitate that may come from zinc, including during storage at 4 °C.
- pH
- Measured directly at 25 °C on each batch; pH drift tracked across stability points.
- Viscosity
- Rotational viscometer with spindle and speed recorded; compared before and after aging to catch a gel thinned by zinc ions.
- Total zinc
- Zinc assayed in the finished product (atomic absorption or ICP — good practice) to show it does not exceed 1% calculated as zinc, all water-soluble zinc salts combined.
- Stability
- Accelerated aging at 40 °C, freeze–thaw cycling and storage at 4 °C in the real packaging at 0, 1 and 3 months; watch for precipitate, color change, separation and viscosity; centrifugation added for the gel-cream.
- Niacinamide content
- For the niacinamide version: HPLC assay at the start and after stability testing.
- Microbiology & challenge test
- Finished product tested at a GLP / ISO 17025-accredited laboratory; preservative efficacy (challenge) test to ISO 11930 — required for a high-water gel.
- Tolerance & human measurement
- Irritation and tolerance testing on volunteers before sign-off; any shine claim only after sebumeter or glossmeter measurement on the finished product itself.
Claims
Claims within the cosmetic scope
The topical data with zinc gluconate we found: a wash-off gel with 2% salicylic acid, 0.2% zinc gluconate and 0.05% lipohydroxy acid, open-label, non-randomized, no control group, 51 people with mild to moderate truncal acne (35 completed) over 84 days, with 6 of 7 authors employed by a company (Towersey et al., 2023); and a cream with pomegranate pericarp extract, salicylic acid, niacinamide, zinc gluconate and other ingredients, randomized split-face (the other half untreated), 16 people with mild to moderate acne over 15 days, with 3 of 5 authors company employees and 1 a consultant (Queille-Roussel et al., 2026). Both are combination formulas in people with acne — the results belong to the whole formula. The trial of zinc gluconate tablets against minocycline (Dreno et al., 2001) is a drug setting; the Brandt review (2013, author employed by a company) gives a grade B recommendation to oral and topical zinc in general; the PPAR-α data come from skin explants kept alive outside the body (Poiraud et al., 2012). Annex 03-MP of Circular 06/2011/TT-BYT does not accept claims of acting on acne as a disease, but suggests the wording “Reduces shine for oily skin” and “Makes your skin feel less oily”. Below is the wording Butter-C recommends.
Reduces shine for oily skin, helps skin feel less oily (only after measurement on the finished product)
Annex 03-MP’s model wording; used only after sebumeter or glossmeter measurement on the finished product itself, as a claim of the whole formula. Instead of: all-day oil control, regulating sebaceous glands, reducing sebum thanks to zinc.
Contains zinc gluconate (Zinc Gluconate) — a water-soluble zinc salt
Ingredient and story statement, with the correct INCI. Instead of: “works like zinc tablets”, borrowing figures from oral trials or the lesion reductions of other formulas.
Moisturizes, helps soften skin
A function of the humectant base (glycerin, betaine, panthenol, sodium hyaluronate); hydration figures only when measured on the finished product. Instead of: restores skin, regenerates skin.
Suitable for oily, combination and blemish-prone skin
Describes skin type, not an effect on acne. Persistent or inflamed acne needs a dermatologist. Instead of: drug-like claims about acne, “reduces breakouts”, claims to act on bacteria.
Skin feels fresh and light
Sensory level, used once a sensory evaluation has been run on the finished product. Instead of: tightens pores, shrinks pores.
Label reminders
“Patch test on a small area before use. Avoid contact with eyes. Stop use if skin becomes red or stings.” Ref 24 has no mandatory label warning. Pregnancy or breastfeeding: not enough data on cosmetics containing zinc gluconate — the consultation advises asking a doctor. This page is a facial gel for adults. Instead of: non-irritating, safe in pregnancy, suitable for children.
Manufacturing specifications
Current capabilities
- Texture
- Clear oil-free gel or milky gel-cream; colorless.
- Format
- Flip-top tubes, pump bottles or jars with a spatula. Volume agreed when choosing packaging.
- Minimum order quantity
- Agreed per order — depends on formula direction and chosen format.
- Testing
- Tested at a GLP / ISO 17025-accredited laboratory, including total zinc assay; certificate of analysis delivered with each batch.
- Dossier
- Product Information File (PIF) and cosmetic product notification prepared by Butter-C, including the zinc calculation table based on the raw material COA.
- Packaging
- Label design, printing and packing run in parallel with formulation; the patch-test and avoid-the-eyes reminders are laid out from the first label draft.
Suggested product concept
Oil-free, fragrance-free clear zinc gluconate – panthenol gel for oily skin
One product direction to help you picture it — not a ready-made product for sale. The actual formula is built around your brand’s positioning and price point.
Zinc Gluconate 0.5%
About 0.07% zinc based on the theoretical 14.4% of the anhydrous form — well below the 1% ceiling calculated as zinc; the exact figure is calculated from the COA and zinc is assayed in the finished product.
Glycerin, Betaine, Panthenol
The humectant group — the basis for a moisturizing claim after testing on the finished product.
Hydroxyethylcellulose framework, no EDTA
A non-ionic polymer that tolerates zinc ions; Phenoxyethanol – Ethylhexylglycerin system; pH set by stability testing.
50 ml flip-top tube, fragrance-free
Used morning and evening after cleansing; label carries patch-test and avoid-the-eyes reminders.
Customization options
What you can specify
The same product type serves different customers for each brand. Tell us your requirements in the areas below and our pharmacists will build the matching formula.
Zinc level
Zinc gluconate percentage, and whether other zinc salts are added — all water-soluble zinc salts are added together and checked against 1% calculated as zinc (Ref 24).
Texture
Clear oil-free gel or milky gel-cream; thickness and how it breaks into water when spread.
Supporting ingredients
Niacinamide, Panthenol, Betaine, Sodium Hyaluronate — chosen by target skin type and tested for compatibility with zinc ions.
If you want a shine claim
Requires sebumeter or glossmeter measurement on the finished product itself; the cost of volunteer testing is quoted separately.
Companion products
Zinc PCA toner, gel cleanser, sunscreen in the same line — when sold as a set, zinc is calculated for each product separately.
Ingredient positioning
Oil-free, fragrance-free, vegan — please state these at the start so suitable raw materials can be chosen.
Further reading
Related knowledge
Zinc gluconate in cosmetics
Separating oral data from topical data, how to calculate zinc and the ASEAN 1% zinc limit (in Vietnamese).
Moisturizing gel manufacturing
General page: gel frameworks, humectants and how polymers tolerate electrolytes.
Zinc PCA toner manufacturing
A different zinc salt not named in Ref 24 — how the limit is applied cautiously.
Niacinamide & zinc serum manufacturing
A stronger direction: a serum with two assayed actives, using the same COA-based zinc calculation.
Oily skin and enlarged pores
Why skin produces excess oil and how far cosmetics can help (in Vietnamese).
Niacinamide in cosmetics
The active most often paired with zinc salts in products for oily skin (in Vietnamese).
How we work
From idea to finished batch
Eight steps and three milestones signed off by both sides: approved sample, notification number, finished batch. Step-by-step details →
Get started
Tell us about the product you plan to launch
Send us your product direction and expected volume. Our team will get back to you during business hours (Vietnam time, GMT+7).
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